Information processing apparatus and method program, and recording medium

ABSTRACT

An encoded bit stream having a frame rate of 24 Hz or 23.976 Hz and a progressive format for both NTSC and PAL is recorded on a recording medium. An encoded stream reproduced from the recording medium is supplied to a decoder  20 . In the decoder  20 , the encoded stream is decoded and 24 p or 23.976 p video is obtained. A video converting portion  25  converts the reproduced video into a display video in accordance with the display format of a monitor  26 . For the NTSC range, 29.97 i or 59.94 p display format can be used. For the PAL range, 25 i or 50 p display format can be used.

TECHNICAL FIELD

The present invention relates to an information processing apparatus anda method for recording sub data that is reproduced in synchronizationwith main audio and video data and to a program for the informationprocessing apparatus and a recording medium on which the program for theinformation processing apparatus is recorded.

BACKGROUND ART

A technology for recording a transport stream of video data that hasbeen encoded in accordance with MPEG2 (Moving Picture Experts GroupPhase 2) to a recording medium for example an optical disc is describedin for example Patent Document 1 (Japanese Patent Laid-Open PublicationNo. 2002-158972).

FIG. 1 shows a picture format of a frame structure of which a videosignal is encoded in accordance with the MPEG. In FIG. 1, dirk stripesrepresent lines of a top field (top_field), whereas white stripesrepresent lines of a bottom field (bottom_field). In the NTSCtransmission picture signal format having an aspect ratio of (4:3), oneframe has a total of 480 lines of 240 lines of the top field and 240lines of the bottom field. The number of pixels in the horizontaldirection is 704 pixels. One bit flag top_field_first of headerinformation of the picture layer represents which of the top field andbottom field is chronologically first displayed. When top_field_first=1,the top field is chronologically first displayed.

FIG. 2 shows a spatial relation between the format of an MPEG decodedpicture and the format of a transmission picture. The format of thetransmission picture is the NTSC format having an aspect ratio of 4:3.An effective pixel area (pixel area of an MPEG decoded picture) of oneframe is composed of 780 pixels×480 lines. The transmission pictureformat includes non-effective areas of a horizontal blanking area and avertical blanking area.

In addition to the foregoing flag top_field_first, another flagrepeat_first_field is also transmitted. The flag repeat_first_field is aflag that represents that there is a repeat field. A film material suchas a movie is data composed of 24 frames per second. In contrast, avideo signal for example an NTSC format video signal has a format of 30frames pre second. Thus, when a film material is converted into a videosignal, a process for generating 30 frames using 24 frames is required.Such a process includes a process for converting two fields into threefields in accordance with a predetermined conversion pattern. Thus, sucha process is generally referred to as 2:3 pull down. In other words, thefirst field is automatically and repeatedly generated twice every fiveframes. As a result, 24 frames are converted into 30 frames.

When a video signal that has been obtained by the foregoing 2:3 pulldown process is compressed in accordance with the MPEG, sinceinformation of fields (repeat fields) that have been inserted forincreasing the number of frames is redundant, the video signal isencoded so that the repeat fields are removed and the compressionefficiency is improved. A process for detecting repeat fields of videodata of which 24 frames per second are converted into 30 frames persecond by the 2:3 pull down process, removing the repeat fields, anddecreasing the number of frames to 24 frames per second is referred toas inverse 2:3 pull down process.

Next, with reference to FIG. 3, the process for converting a filmmaterial of 24 frames per second into an NTSC format television materialof 30 frames per second, namely the 2:3 pull down process, will bedescribed. A film material is composed of two frames per second. Twofields (first and second fields) of the same picture are composed ofeach field of the film material. As a result, a picture signal of 48fields per second is generated. Thereafter, four frames (eight fields)of the film material are converted into five frames (10 fields) of avideo signal, for example an NTSC format video signal.

In FIG. 3, a chronologically last field of three fields surrounded by atrapezoid is a field that is repeated to increase the number of fields,namely a repeat first field. The repeat first field takes place twiceevery five frames. The video signal for which the 2:3 pull down processhas been performed is accompanied by two flags top_field_first andrepeat_first_field. In the frame first structure, the flagtop_field_first is a flag that represents whether the first field is topor bottom. The flag repeat_first_field is a flag that represents thatthere is a repeat field.

As described above, when a video signal is encoded in accordance withthe MPEG2 and the frame frequency of the NTSC format is 29.97 Hz, valuesof the two flags top_field_first and repeat_first_field are set for eachpicture. In addition, frame_rate of the sequence header is set for 29.97Hz.

As another television format, PAL format is also known as well as theNTSC format. The PAL format whose aspect ratio is (4:3) has a framefrequency of 25 Hz and a structure of which one frame is composed of 720(pixels)×576 (lines). In the PAL format, basically, top_field_first=1,repeat_first_field=0, and frame_rate of the sequence header=25 Hz areset. In other words, a top field and a bottom field are made of oneframe of a movie. The obtained video signal is recorded on a recodingmedium. Thus, in the PAL format, the reproduction speed of the videosignal is faster than that of the original movie by 25/24 times.

As described above, in a standard resolution format, the NTSC format isdifferent from the PAL format in the picture size and the frame rate.However, in for example a high resolution (HD: High Definition) format,the picture size of the NTSC format is the same as that of the PALformat. Thus, when a movie source is converted into a video signal ineach format, it is necessary to convert only the frame rate. These twoformats whose frame rates are different and whose picture sizes arecommon are referred to as NTSC range and PAL range.

Conventionally, the format of an original video signal converted into anNTSC video signal was different from the format of an original videosignal converted into a PAL video signal. Thus, to author a recordingmedium on which for example a movie source is recorded, video signalsthat can be suitably converted into both the formats should be prepared.Thus, it was laborious to handle video signals in both the formats.

Recently, a progressive format display monitor has been used. So far, inthe NTSC format, it was difficult to convert a 29.97 Hz interlacedmoving picture into a 59.94 (=2×30×(1000/1001)) Hz progressive movingpicture and display the converted picture. Since a video signal forwhich the 2:3 pull down process had been performed may have beenirregularly encoded, it was not easy to detect a progressive frame froma decoded moving picture of an MPEG2 video stream.

In addition, in the PAL format, a movie source of 24 frames per secondis fast reproduced at a frame rate of 25 Hz. Thus, the reproductionspeed of a video signal is faster than that of an original movie by25/24 times. As a result, the pitch of audio becomes high.

Thus, an object of the present invention is to provide an informationprocessing apparatus and method, a program, and a recording medium thatallow encoding to be performed in common with the NTSC range and the PALrange, a moving picture of the NTSC range to be easily converted into a59.94 Hz progressive moving picture, and a reproduction speed of the PALrange to be prevented from being increased by 25/24 times over that ofthe original.

DISCLOSURE OF THE INVENTION

To solve the foregoing problem, claim 1 of the present invention is aninformation processing apparatus for recording a video signal that canbe displayed at all frame rates of 29.97 Hz, 59.94 Hz, 25 Hz, and 50 Hzon a recording medium, comprising:

compression encoding means for generating an encoded video bit streamhaving a size in common with an NTSC range and a PAL range, a frame rateof 24 Hz or 23.976 Hz, and a progressive format; and

recording means for recording the encoded video bit stream on therecording medium.

A non-limiting embodiment of the present invention is an informationprocessing method for recording a video signal that can be displayed atall frame rates of 29.97 Hz, 59.94 Hz, 25 Hz, and 50 Hz on a recordingmedium, comprising the steps of:

generating an encoded video bit stream having a size in common with anNTSC range and a PAL range, a frame rate of 24 Hz or 23.976 Hz, and aprogressive format; and

recording the encoded video bit stream on the recording medium.

A non-limiting embodiment of the present invention is a program for aninformation processing apparatus for recording a video signal that canbe displayed at all frame rates of 29.97 Hz, 59.94 Hz, 25 Hz, and 50 Hzon a recording medium, the program comprising the steps of:

generating an encoded video bit stream having a frame rate of 24 Hz or23.976 Hz and a progressive format; and

recording the encoded video bit stream on the recording medium.

A non-limiting embodiment of the present invention is a recording mediumon which a computer readable program for an information processingapparatus for recording a video signal displayed at a frame rate of29.97 Hz, 59.94 Hz, 25 Hz, or 50 Hz is recorded, the program comprisingthe steps of:

generating an encoded video bit stream having a size in common with anNTSC range and a PAL range, a frame rate of 24 Hz or 23.976 Hz, and aprogressive format; and

recording the encoded video bit stream on the recording medium.

A non-limiting embodiment of the present invention is a recording mediumon which a video signal that can be displayed at all frame rates of29.97 Hz, 59.94 Hz, 25 Hz, and 50 Hz is recorded as a compressionencoded video bit stream having a size in common with an NTSC range anda PAL range, a frame rate of 24 Hz or 23.976 Hz, and a progressiveformat.

A non-limiting embodiment of the present invention is an informationprocessing apparatus for reproducing from a recording medium acompression encoded video bit stream having a picture size in commonwith an NTSC range and a PAL range, a frame rate of 24 Hz or 23.976 Hz,and a progressive format, the information processing apparatuscomprising:

means for reproducing the encoded video bit stream from the recordingmedium;

decompression decoding means for decoding the reproduced encoded videobit stream and generating a video signal having a frame rate of 23.976Hz or 24 Hz and a progressive format; and

video converting means for converting an output of the decompressiondecoding means into a video signal having a frame rate of 29.97 Hz,59.94 Hz, 25 Hz, or 50 Hz.

A non-limiting embodiment of the present invention is a program for aninformation processing apparatus for reproducing from a recording mediuma compression encoded video bit stream having a picture size in commonwith an NTSC range and a PAL range, a frame rate of 24 Hz or 23.976 Hz,and a progressive format, the program comprising the steps of:

reproducing the encoded video bit stream from the recording medium;

decoding the reproduced encoded video bit stream and generating a videosignal having a frame rate of 23.976 Hz or 24 Hz and a progressiveformat; and

converting a video signal obtained at the decompression decoding stepinto a video signal having a frame rate of 29.97 Hz, 59.94 Hz, 25 Hz, or50 Hz.

A non-limiting embodiment of the present invention is a recording mediumon which a computer readable program for an information processingapparatus for reproducing from a recording medium a compression encodedvideo bit stream having a picture size in common with an NTSC range anda PAL range, a frame rate of 24 Hz or 23.976 Hz, and a progressiveformat is recorded, the program comprising the steps of:

reproducing the encoded video bit stream from the recording medium;

decoding the reproduced encoded video bit stream and generating a videosignal having a frame rate of 23.976 Hz or 24 Hz and a progressiveformat; and

converting a video signal obtained at the decompression decoding stepinto a video signal having a frame rate of 29.97 Hz, 59.94 Hz, 25 Hz, or50 Hz.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram describing an MPEG decoding pictureformat.

FIG. 2 is a schematic diagram describing a relation of the format of anMPEG decoding picture and the format of a transmission picture.

FIG. 3 is a schematic diagram describing a conventional 2:3 pull downprocess.

FIGS. 4A and 4B are schematic diagrams describing a format on a discaccording to an embodiment of the present invention.

FIG. 5 is a block diagram showing an encoder system according to theembodiment of the present invention.

FIG. 6 is a block diagram showing a decoder system according to theembodiment of the present invention.

FIG. 7 is a schematic diagram describing a display format convertingprocess for a video signal according to the embodiment of the presentinvention.

FIG. 8 is a schematic diagram describing a converting process from 24pinto 30i and a converting process from 24p into 60p.

FIG. 9 is a schematic diagram describing a converting process from23.976p into 29.97i and a converting process from 23.976p into 59.94p.

FIGS. 10A and 10B are schematic diagrams describing a converting processfrom 24p into 29.97i and a converting process from 24p into 59.94p.

FIG. 11 is a schematic diagram describing a converting process from 24pinto 25i and a converting process from 24p into 50p.

FIGS. 12A and 12B are schematic diagrams showing a converting processfrom 23.976p into 25i and a converting process from 23.976p into 50p.

FIG. 13 is a flow chart showing a flow of a process of a reproducingmethod applied for the NTSC range according to the present invention.

FIG. 14 is a flow chart showing a flow of a process of a reproducingmethod applied for the PAL range according to the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

Next, with reference to the accompanying drawings, an embodiment of thepresent invention will be described. According to the present invention,it is assumed that the video format (for example, MPEG2 format) for arecording medium is a 24 Hz (or 23.976 Hz (=24×(1000/1001) Hz)progressive format. On the other hand, as shown in FIG. 4A, as HD videotelevision formats of effective picture area H×V (1920×1080), 29.97i(interlaced video signal having a frame rate of 29.97 Hz) for the NTSCrange and 25i (interlaced video signal having a frame rate of 25 Hz) forthe PAL range have been standardized.

According to the present invention, as shown in FIG. 4B, for both theNTSC range and the PAL range, for example an MPEG2 video bit stream isrecorded on a recoding medium in a 24p or 23.976p (a progressive videosignal having a frame rate of 24 Hz or 23.976 Hz) video format. Thepresent invention can be also applied to another picture size(1440×1080) of an HD video signal.

Conventionally, as shown in FIG. 4A, for effective picture area H×V(1280×720), 59.94p (a progressive video signal having a frame rate of59.94 Hz) and 50p (a progressive video signal having a frame rate of 50Hz) have been standardized as HD video television formats for the NTSCrange and the PAL range, respectively.

In this case, according to the present invention, as shown in FIG. 4B,for both the NTSC range and the PAL range, for example an MPEG2 videobit stream is recorded on a recoding medium in 24p or 23.976p videoformat. A frame rate, 24 Hz, of a video format for a recording mediumcorresponds to 24 frames per second of an original movie source. A framerate, 23.976 Hz, is a frequency at which a display signal of a monitorcan be easily converted into a frame rate of 29.97 Hz of a displaysignal of a monitor. In other words, there is a relation of (23.976Hz×(5/4)=29.97 Hz). Thus, the 2:3 pull down process for converting theframe rate of 24 Hz into the frame rate of 30 Hz can be used as it is.

On a player side that reproduces from a recording medium a movie sourcewhose frame rate has been converted and for which an encoding processfor example an MPEG2 encoding process have been performed, reproducedvideo data is converted into a video format in accordance with firstdetermination that represents whether the video format of the recordingmedium is 24p or 23.976p and second determination that representswhether the display video format of a display monitor (for the NTSCrange) is 29.97i or 59.94p or that (for the PAL range) is 25i or 50p.

Next, the embodiment of the present invention will be described. In FIG.5, reference numeral 10 represents an MPEG2 video encoder. As an inputsignal, a 24 Hz (or 23.976 Hz) digital progressive video signal producedfrom a movie source film is prepared. The input video signal can beproduced in the following two methods.

As the first method, a movie source of 24 frames per second is convertedinto a 24 Hz (or 23.976 Hz) progressive video signal. As the secondmethod, a movie source is converted into a 30 Hz (or 29.97 Hz)interlaced video signal by the 2:3 pull down process. Thereafter, theinterlaced video signal is inversely converted by the inverse 2:3 pulldown process. As a result, a 24 Hz (or 23.976 Hz) progressive videosignal is restored. When the first and second methods are compared, thefirst method is preferable because the amount of the process is small.Since there is a relation of 23.976 Hz (=24×(1000/1001) Hz), when the 24Hz progressive video signal is thinned out by one frame from every 1001frames, a 23.976 Hz progressive video signal can be generated.

The MPEG2 video encoder 10 encodes the input video signal and outputs anMPEG2 video bit stream having the following parameters.

-   -   frame_rate=24 Hz (or 23.976 Hz)    -   progressive_sequence=1    -   top_field_first=0, repeat_first_field=0

The value of frame_rate is the same as the frame rate of the input videosignal (24 Hz or 23.976 Hz).

As shown in FIG. 5, an MPEG2 video bit stream (V) is multiplexed with anaudio stream (A) and system information (S) by a multiplexer 11. As aresult, the multiplexer 11 outputs a transport stream. An ECC (ErrorCorrection Code) encoding portion 12 performs an error correction codeencoding process for the transport stream. A modulating portion 13performs a digital modulating process for an output of the ECC encodingportion 12. An output of the modulating portion 13 is supplied to awriting portion 14. The writing portion 14 records an output of themodulating portion 13 on a recording medium, for example an optical disc15.

FIG. 6 shows a structure of an example of a decoder system that decodesan MPEG2 video bit stream reproduced from a recording medium, forexample an optical disc 15 on which an output of the foregoing videoencoder 10 has been recorded. Data reproduced from the optical disc 15by a reading portion 20 is digitally demodulated by a demodulatingportion 21. An ECC decoding portion 22 performs an error correction codedecoding process for an output of the demodulating portion 21. An outputof the ECC decoding portion 22 is supplied to a demultiplexer 23. Thedemultiplexer 23 demultiplexes the output of the demodulating portion 21into a video bit stream (V), an audio stream (A), and system information(S). The video bit stream (V) is input to an MPEG2 video encoderdesignated by reference numeral 24. The encoder 24 outputs a 24 Hz (or23.976 Hz) progressive moving picture to a video converting portion 25.The value of the frame rate is the same as frame rate of the MPEG2 videobit stream.

A video signal that is output from the video converting portion 25 issupplied to a monitor 26. The monitor 26 displays the video signal. Acontrol signal that designates a display format of the display monitoris supplied to the video converting portion 25. The video convertingportion 25 converts the 24 Hz (or 23.976 Hz) progressive moving pictureinto a video signal having a designated display format.

FIG. 7 shows a list of converting processes performed by the videoconverting portion 25. Each converting method will be described in thefollowing.

For the converting processes performed by the video converting portion25, a converting process from 24p into 30i and a converting process from24p into 60p are performed. As a result, intermediate signals of 30i and60p are generated. A signal reproduced from a disc is a progressivesignal (24p) composed of 24 encoded frames per second. The convertingprocess from 24p into 30i is the same as the 2:3 pull down convertingprocess described with reference to FIG. 3 except that the picture sizeis in an HD format. In other words, a process for converting two fieldsinto three fields in accordance with a predetermined conversion patternis performed. The first field is repeatedly generated twice every fivedisplay frames. As a result, 24p is converted into 30i. When 24p isconverted into 60p, the first frame and the next frame are repeatedtwice and three times, respectively, every two frames of the 24p encodedframes. As a result, a 60p video signal is obtained.

FIG. 9 shows a converting process in the case that the display format isthe NTSC range and the disc format is 23.976p. A converting process from23.976p into 29.97i is a process for converting a progressive videosignal having a frame rate of 23.976 Hz into an interlaced video signalhaving a frame rate of 23.97 Hz. A converting process from 23.976p into59.94p is a process for converting a progressive video signal having aframe rate of 23.976 Hz into a progressive video signal having a framerate of 59.94 Hz.

When 23.976p is converted into 29.97i, like the converting process from24p into 30i shown in FIG. 8, a 23.976p encoded frame is converted intoan interlaced video signal by the 2:3 pull down process. When 23.976p isconverted into 59.94p, like the converting process from 24p into 60pshown in FIG. 8, the first frame and the next frame are repeated twiceand three times, respectively, every two frames of the 23.976p encodedframes. As a result, a 59.94 Hz progressive video signal is obtained.

FIG. 10 shows a converting process in the case that the display formatis the NTSC range and the disc format is 24p. A converting process from24p into 29.97i is a process for converting a progressive video signalhaving a frame rate of 24 Hz into an interlaced video signal having aframe rate of 29.97 Hz. A converting process from 24p into 59.94p is aprocess for converting a progressive video signal having a frame rate of24 Hz into a progressive video signal having a frame rate of 59.94 Hz.

For the NTSC range, the converting process from 24p into 29.97i and theconverting process from 24p into 59.94i can be performed by addinganother process for 30i generated from 24p and a video signal as anintermediate signal of 60p. Since there is a relation of 29.97 Hz(=30×(1000/1001) Hz), by thinning out one display frame from every 1001display frames of the 30i signal, a 29.97i signal can be generated. Inaddition, since there is a relation of (1/60)×1001×(1/1000)=(1/59.94),by thinning out one display frame from every 1001 display frames of the60p signal, a 59.94p signal can be generated.

Next, a practical example of the thin-out process will be described. A30i signal for one minute is composed of 1800 display frames. Thus, bythinning out two frames every minute except for 0, 10, 20, 30, 40, and50 minutes, one display frame can be substantially thinned out fromevery 1001 display frames. As a result, a 29.97i signal can begenerated. In addition, a 60p signal for one minute is composed of 3600frames. Thus, by thinning out four frames every minute except for 0, 10,20, 30, 40, and 50 minutes, one display frame can be substantiallythinned out from every 1001 display frames. As a result, a 59.94p signalcan be generated. A process for not thinning out a display frame isnormally referred to as a process for a drop frame.

FIG. 11 shows a converting process in the case that the display formatis the PAL range and that the disc format is 24p. A converting processfrom 24p into 25i is a process for converting a progressive video signalhaving a frame rate of 24 Hz into an interlaced video signal having aframe rate of 25 Hz. A converting process from 24p into 50p is a processfor converting a progressive video signal having a frame rate of 24 Hzinto a progressive video signal having a frame rate of 50 Hz.

When 24p is converted into 25i, the first 11 encoded frames and the lastone encoded frame are repeatedly displayed for two fields and for threefields, respectively, every 12 encoded frames. As a result, aninterlaced video signal having a frame rate of 25 Hz is generated. When24p is converted into 50p, the first 11 encoded frames and the last oneencoded frame are repeatedly displayed for two frames and three frames,respectively, every 12 encoded frames. As a result, a progressive videosignal having a frame rate of 50 Hz is generated.

FIG. 12 shows a converting process in the case that the display formatis the PAL range and that the disc format is 23.976p. A convertingprocess from 23.976p into 25i is a process for converting a progressivevideo signal having a frame rate of 23.976 Hz into an interlaced videosignal having a frame rate of 25 Hz. A converting process from 23.976pinto 50p is a process for converting a progressive video signal having aframe rate of 23.976 Hz into a progressive video signal having a framerate of 50 Hz.

When 23.976p is converted into 25i, the first 11 encoded frames and thelast one encoded frame are repeatedly displayed for two fields and threefields, respectively, every 12 encoded frames. In addition, one displayframe is inserted into every 1000 display frames. As a result, aninterlaced video signal having a frame rate of 25 Hz is generated. When23.976p is converted into 50p, the first 11 encoded frames and the lastone encoded frame are repeatedly displayed for two frames and threeframes, respectively, every 12 encoded frames. In addition, two displayframes are inserted into every 2000 display frames. As a result, aprogressive video signal having a frame rate of 50 Hz is generated.

FIG. 13 is a flow chart applied for a reproducing method in the casethat the display format is the NTSC range and the disc format is 24p or23.976p. At the first step S101, it is determined whether the frame rateof the disc format is 24 Hz or 23.976 Hz in accordance with informationof a sequence layer of an MPEG2 video bit stream reproduced from thedisc. When the frame rate is 23.976 Hz, the process advances to stepS102. When the frame rate is 24 Hz, the process advances to step S105.

At step S102, it is determined whether or not the display format of themonitor is 29.97i or 54.94p. When the display format is 29.97i, theprocess advances to step S103. When the display format is 54.94p, theprocess advances to step S104.

At step S103, a converting process from 24p into 29.97i is performed. Inother words, as described with reference to FIG. 8, two fields and threefields are repeatedly displayed every two encoded frames. As a result, a30i video signal is generated. In addition, as described with referenceto FIG. 10, a process for thinning out one display frame from every 1000display frames of the 30i video signal is preformed. As a result, aninterlaced video signal having a frame rate of 29.97 Hz is generated.

At step S104, a converting process from 24p into 54.94p is performed. Inother words, as described with reference to FIG. 8, two frames and threeframes are repeatedly displayed every two encoded frames. As a result a60p video signal is generated. In addition, as described with referenceto FIG. 10, a process for thinning out one display frame from every 1000display frames of the 60p video signal is performed. As a result, aprogressive video signal having a frame rate of 59.94 Hz is generated.

When the determined result at step S101 represents that the disc formatis 23.976 Hz, at step S105, it is determined whether the display formatof the monitor is 29.97i or 54.94p. When the display format is 29.97i,the process advances to step S106. When the display format is 54.94p,the process advances to step S107.

At step S106, a converting process from 23.976p into 29.97i isperformed. In other words, as described with reference to FIG. 9, aprocess for repeatedly displaying two fields and three fields every twoencoded frames is performed. As a result, an interlaced video signalhaving a frame rate of 29.97 Hz is generated.

At step S107, a converting process from 23.976p into 54.94p isperformed. In other words, as described with reference to FIG. 9, aprocess for repeatedly displaying two frames and three frames every twoencoded frames is preformed. As a result, a progressive video signalhaving a frame rate of 59.94 Hz is generated.

FIG. 14 a flow chart applied for a reproducing method in the case thatthe display format is the PAL range and the disc format is 24p or23.976p. At the first step S201, it is determined whether the frame rateof the disc format is 24 Hz or 23.976 Hz in accordance with informationof the sequence layer. When the frame rate is 24 Hz, the processadvances to step S202. When the frame rate is 23.976 Hz, the processadvances to step S205.

At step S202, it is determined whether the display format of the monitoris 25i or 50p. When the display format is 25i, the process advances tostep S203. When the display format is 50p, the process advances to stepS204.

At step S203, a converting process from 24p into 25i is performed. Inother words, as described with reference to FIG. 11, the first 11encoded frames and the last one encoded frame are repeatedly displayedfor two fields and three fields, respectively, every 12 encoded framesof 24p. As a result, an interlaced video signal having a frame rate of25 Hz is generated.

At step S204, a converting process from 24p into 50p is performed. Inother words, as described with reference to FIG. 11, the first 11encoded frames and the last one encoded frame are repeatedly displayedfor two frames and three frames, respectively, every 12 encoded frames.As a result, a progressive video signal having a frame rate of 50 Hz isgenerated.

When the determined result at step S201 represents that the disc formatis 23.976 Hz, at step S205, it is determined whether the display formatof the monitor is 25i or 50p. When the display format is 25i, theprocess advances to step S206. When the display format is 50p, theprocess advances to step S207.

At step S206, a converting process from 23.976p into 25i is performed.In other words, the first 11 encoded frames and the last one encodedframe are repeatedly displayed for two fields and three fields,respectively, every 12 encoded frames. In addition, as described withreference to FIG. 12, one display frame is inserted into every 1000display frames. As a result, an interlaced video signal having a framerate of 25 Hz is generated.

At step S207, a converting process from 23.976p into 50p is performed.In other words, the first 11 encoded frames and the last one encodedframe are repeatedly displayed for two frames and three frames,respectively, every 12 encoded frames. In addition, as described withreference to FIG. 12, one display frame is inserted into every 1000display frames. As a result, a progressive video signal having a framerate of 50 Hz is generated.

Although the present invention has been shown and described with respectto a best mode embodiment thereof, it should be understood by thoseskilled in the art that the foregoing and various other changes,omissions, and additions in the form and detail thereof may be madetherein without departing from the spirit and scope of the presentinvention. For example, according to the present invention, the framerate of a video signal recorded on a recording medium may be fixed toone of 24 Hz or 23.976 Hz. In addition, the present invention can beapplied to the case that a movie source is converted into a video formatother than MPEG2. In addition, the present invention can be applied tothe case that bit stream data is recorded in a recording medium otherthan a disc, for example a semiconductor memory. In addition, the videoconverting portion 25 may be accomplished by software using amicroprocessor and a memory that stores a program as well as hardware.

Conventionally, when a video signal (having a frame rate of 29.97 Hz forthe NTSC range and a frame rate of 25 Hz for the PAL range) obtainedfrom a film material of 24 frames per second is encoded, differentprocesses are performed for the NTSC range and PAL range. In contrast,according to the present invention, a common encoding process can beperformed by a common encoder system for both the NTSC range and PALrange.

For the NTSC range, it was difficult to convert an interlaced movingpicture having a frame rate of 29.97 Hz into a progressive movingpicture having a frame rate of 59.94 Hz. In contrast, according to thepresent invention, a progressive moving picture is recorded on arecording medium. Thus, according to the present invention, for the NTSCrange, a progressive moving picture having a frame rate of 24 Hz or23.976 Hz can be easily converted into an interlaced moving picturehaving a frame rate of 29.97 Hz or a progressive moving picture having aframe rate of 59.94 Hz and displayed. In addition, according to thepresent invention, for the PAL range, a progressive moving picturehaving a frame rate of 24 Hz or 23.976 Hz can be easily converted intoan interlaced moving picture having a frame rate of 25 Hz or aprogressive moving picture having a frame rate of 50 Hz and displayed.

According to the present invention, for the PAL range, a problem ofwhich the reproduction speed of a video signal is faster than that ofthe original movie by (25/24 times). Thus, the reproduction speed of thevideo signal becomes the same as that of the original.

When a movie is taped by a HDTV video camera having a frame rate of 24Hz, according to the present invention, since a video material can bedirectly input to an MPEG video encoder, the video material can beconveniently handled.

DESCRIPTION OF REFERENCE NUMERALS

-   10 MPEG2 VIDEO ENCODER-   24 MPEG2 VIDEO DECODER-   25 VIDEO CONVERTING PORTION-   26 MONITOR-   S101, S201 Frame_rate=24 or 23.976?-   S102, S105 29.97i or 54.94p?-   S103 REPEATEDLY DISPLAY TWO FIELDS AND THREE FIELDS EVERY TWO    ENCODED FRAMES. IN ADDITION, THIN OUT ONE DISPLAY FRAME FROM EVERY    1000 DISPLAY FRAMES.-   S104 REPEATEDLY DISPLAY TWO FRAMES AND THREE FRAMES EVERY TWO    ENCODED FRAMES. IN ADDITION, THIN OUT ONE DISPLAY FRAME FROM EVERY    1000 DISPLAY FRAMES.-   S106 REPEATEDLY DISPLAY TWO FIELDS AND THREE FIELDS EVERY TWO    ENCODED FRAMES.-   S107 REPEATEDLY DISPLAY TWO FRAMES AND THREE FRAMES EVERY TWO    ENCODED FRAMES.-   S202, S205 25i or 50p?-   S203 REPEATEDLY DISPLAY FIRST 11 ENCODED FRAMES AND LAST ONE ENCODED    FRAME FOR TWO FIELDS AND THREE FIELD, RESPECTIVELY, EVERY 12 ENCODED    FRAMES.-   S204 REPEATEDLY DISPLAY FIRST 11 ENCODED FRAMES AND LAST ONE ENCODED    FRAME FOR TWO FRAMES AND THREE FRAMES, RESPECTIVELY, EVERY 12    ENCODED FRAMES.-   S206 REPEATEDLY DISPLAY FIRST 11 ENCODED FRAMES AND LAST ONE ENCODED    FRAME FOR TWO FIELDS AND THREE FIELDS, RESPECTIVELY, EVERY 12    ENCODED FRAMES. IN ADDITION, INSERT ONE DISPLAY FRAME INTO EVERY    1000 DISPLAY FRAMES.-   S207 REPEATEDLY DISPLAY FIRST 11 ENCODED FRAMES AND LAST ONE ENCODED    FRAME FOR TWO FIELDS AND THREE FRAMES, RESPECTIVELY, EVERY 12    ENCODED FRAMES. IN ADDITION, INSERT ONE DISPLAY FRAME INTO EVERY    1000 DISPLAY FRAMES.

1. An information processing apparatus for reproducing from a recordingmedium a compression encoded video bit stream having a picture size incommon with an NTSC range and a PAL range, a frame rate of 24 Hz or23.976 Hz, and a progressive format, the information processingapparatus comprising: when the display format is the PAL range, meansfor reproducing the encoded video bit stream from the recording medium;decompression decoding means for decoding the reproduced encoded videobit stream and generating a video signal having a frame rate of 23.976Hz or 24 Hz and a progressive format; video converting means forconverting an output of the decompression decoding means into a videosignal having a frame rate of 29.97 Hz, 59.94 Hz, 25 Hz, or 50 Hz; firstdetermining means for determining whether the frame rate of the videosignal on the recording medium is 24 Hz or 23.976 Hz; and seconddetermining means for determining whether the display format of thevideo signal is 25 Hz or 50 Hz; wherein when the first determined valueof the first determining means is 24 Hz, and when the second determinedvalue of the second determining means is 25 Hz, the video convertingmeans performs processing of displaying the first 11 encoded frames andthe last one encoded frame repeatedly for two frames and three frames,respectively, every 12 encoded frames, and further performs processingof inserting one display frame into every 1000 display frames, and whenthe second determined value of the second determining means is 50 Hz,the video converting means performs processing of displaying the first11 encoded frames and the last one encoded frame repeatedly for twoframes and three frames, respectively, every 12 encoded frames, andfurther performs processing of inserting one display frame into every1000 display frames.
 2. An information processing apparatus forreproducing from a recording medium a compression encoded video bitstream having a picture size in common with an NTSC range and a PALrange, a frame rate of 24 Hz or 23.976 Hz, and a progressive format, theinformation processing apparatus comprising: when the display format isthe NTSC range, means for reproducing the encoded video bit stream fromthe recording medium; decompression decoding means for decoding thereproduced encoded video bit stream and generating a video signal havinga frame rate of 23.976 Hz or 24 Hz and a progressive format; videoconverting means for converting an output of the decompression decodingmeans into a video signal having a frame rate of 29.97 Hz, 59.94 Hz, 25Hz, or 50 Hz: first determining means for determining whether the framerate of video signal on the recording medium is 24 Hz or 23.976 Hz; andsecond determining means for determining whether the display format ofvideo signal is 29.97 Hz or 59.94 Hz, wherein when a first determinedvalue of the first determining means is 24 Hz, and when a seconddetermined value of the second determining means is 29.97 Hz, the videoconverting means performs processing of displaying two fields and threefields repeatedly every two encoded frames and further performsprocessing of thinning out one display frame from every 1000 displayframes of the video signal, and when the second determined value of thesecond determining means is 59.94 Hz, the video converting meansperforms processing of displaying two frames and three frames repeatedlyevery two encoded frames and further performs processing of thinning outone display frame from every 1000 display frames of the video signal,wherein when the first determined value of the first determining meansis 23.976 Hz, and when the second determined value of the seconddetermining means is 25 Hz, the video converting means performsprocessing of displaying the first 11 encoded frames and the last oneencoded frame repeatedly for two frames and three frames, respectively,every 12 encoded frames, and when the second determined value of thesecond determining means is 50 Hz, the video converting means performsprocessing of displaying the first 11 encoded frames and the last oneencoded frame repeatedly for two frames and three frames, respectively,every 12 encoded frames.
 3. A computer-readable storage medium storinginstructions which when executed by a computer perform an informationprocessing method, for an information processing apparatus, forreproducing from a recording medium a compression encoded video bitstream having a picture size in common with an NTSC range and a PALrange, a frame rate of 24 Hz or 23.976 Hz, and a progressive format isrecorded, the method comprising: when the display format is the NTSCrange, reproducing the encoded video bit stream from the recordingmedium; decoding the reproduced encoded video bit stream and generatinga video signal having a frame rate of 23.976 Hz and a progressiveformat; and converting a video signal obtained at the decompressiondecoding step into a video signal having a frame rate of 29.97 Hz, 59.94Hz, 25 Hz, or 50 Hz; determining whether the frame rate of the videosignal on the recording medium is 24 Hz or 23.976 Hz; and determiningwhether the display format of the video signal is 29.97 Hz or 59.94 Hz;wherein when it is determined that the frame rate of the video signal is24 Hz, and when it is determined that the display format of the videosignal is 29.97 Hz, video converting is performed which includesdisplaying two fields and three fields repeatedly every two encodedframes and thinning out one display frame from every 1000 display framesof the video signal, and when it is determined that the display formatof the video signal is 59.94 Hz, video converting is performed whichincludes displaying two frames and three frames repeatedly every twoencoded frames and thinning out one display frame from every 1000display frames of the video signal, wherein when it is determined thatthe frame rate of the video signal is 23.976 Hz, and when it isdetermined that the display format of the video signal is 25 Hz, videoconverting is performed that includes displaying the first 11 encodedframes and the last one encoded frame repeatedly for two frames andthree frames, respectively, every 12 encoded frames and when it isdetermined that the display format of the video signal is 50 Hz, videoconverting is performed that includes displaying the first 11 encodedframes and the last one encoded frame repeatedly for two frames andthree frames, respectively, every 12 encoded frames.
 4. An informationprocessing method for an information processing apparatus forreproducing from a recording medium a compression encoded video bitstream having a picture size in common with an NTSC range and a PALrange, a frame rate of 24 Hz or 23.976 Hz, and a progressive format isrecorded, the method comprising: when the display format is the NTSCrange, reproducing in the information processing apparatus the encodedvideo bit stream from the recording medium; decoding in the informationprocessing apparatus the reproduced encoded video bit stream andgenerating a video signal having a frame rate of 23.976 Hz and aprogressive format; converting in the information processing apparatus avideo signal obtained in the decoding into a video signal having a framerate of 29.97 Hz, 59.94 Hz, 25 Hz, or 50 Hz; determining in theinformation processing apparatus whether the frame rate of the videosignal on the recording medium is 24 Hz or 23.976 Hz; and determining inthe information processing apparatus whether the display format of thevideo signal is 29.97 Hz or 59.94 Hz, wherein when it is determined thatthe frame rate of the video signal is 24 Hz, and when it is determinedthat the display format of the video signal is 29.97 Hz, videoconverting is performed which includes displaying two fields and threefields repeatedly every two encoded frames and thinning out one displayframe from every 1000 display frames of the video signal, and when it isdetermined that the display format of the video signal is 59.94 Hz,video converting is performed which includes displaying two frames andthree frames repeatedly every two encoded frames and thinning out onedisplay frame from every 1000 display frames of the video signal,wherein when it is determined that the frame rate of the video signal is23.976 Hz, and when it is determined that the display format of thevideo signal is 25 Hz, video converting is performed that includesdisplaying the first 11 encoded frames and the last one encoded framerepeatedly for two frames and three frames, respectively, every 12encoded frames, and when it is determined that the display format of thevideo signal is 50 Hz, video converting is performed that includesdisplaying the first 11 encoded frames and the last one encoded framerepeatedly for two frames and three frames, respectively, every 12encoded frames.
 5. An information processing method for an informationprocessing apparatus for reproducing from a recording medium acompression encoded video bit stream having a picture size in commonwith an NTSC range and a PAL range, a frame rate of 24 Hz or 23.976 Hz,and a progressive format, the information processing method comprising:when the display format is the PAL range, reproducing in the in theinformation processing apparatus the encoded video bit stream from therecording medium; decoding in the information processing apparatus thereproduced encoded video bit stream and generating a video signal havinga frame rate of 23.976 Hz or 24 Hz and a progressive format; convertingin the information processing apparatus an output of the decoding into avideo signal having a frame rate of 29.97 Hz, 59.94 Hz, 25 Hz, or 50 Hz;determining in the information processing apparatus whether the framerate of the video signal on the recording medium is 24 Hz or 23.976 Hz;and determining in the information processing apparatus whether thedisplay format of the video signal is 25 Hz or 50 Hz; wherein when it isdetermined that the frame rate of the video signal is 24 Hz, and when itis determined that the display format of the video signal is 25 Hz,video converting is performed which includes displaying the first 11encoded frames and the last one encoded frame repeatedly for two framesand three frames, respectively, every 12 encoded frames, and insertingone display frame into every 1000 display frames, and when it isdetermined that the display format of the video signal is 50 Hz, videoconverting is performed which includes displaying the first 11 encodedframes and the last one encoded frame repeatedly for two frames andthree frames, respectively, every 12 encoded frames, and inserting onedisplay frame into every 1000 display frames.
 6. A computer-readablestorage medium storing instructions which when executed by a computerperform an information processing method, for an information processingapparatus, for reproducing from a recording medium a compression encodedvideo bit stream having a picture size in common with an NTSC range anda PAL range, a frame rate of 24 Hz or 23.976 Hz, and a progressiveformat, the method comprising: when the display format is the PAL range,reproducing in the in the information processing apparatus the encodedvideo bit stream from the recording medium; decoding in the informationprocessing apparatus the reproduced encoded video bit stream andgenerating a video signal having a frame rate of 23.976 Hz or 24 Hz anda progressive format; converting in the information processing apparatusan output of the decoding into a video signal having a frame rate of29.97 Hz, 59.94 Hz, 25 Hz, or 50 Hz; determining in the informationprocessing apparatus whether the frame rate of the video signal on therecording medium is 24 Hz or 23.976 Hz; and determining in theinformation processing apparatus whether the display format of the videosignal is 25 Hz or 50 Hz; wherein when it is determined that the framerate of the video signal is 24 Hz, and when it is determined that thedisplay format of the video signal is 25 Hz, video converting isperformed which includes displaying the first 11 encoded frames and thelast one encoded frame repeatedly for two frames and three frames,respectively, every 12 encoded frames, and inserting one display frameinto every 1000 display frames, and when it is determined that thedisplay format of the video signal is 50 Hz, video converting isperformed which includes displaying the first 11 encoded frames and thelast one encoded frame repeatedly for two frames and three frames,respectively, every 12 encoded frames, and inserting one display frameinto every 1000 display frames.